WOODBURY, N.Y. (WCBS 880/CBS 2) – The weight of so much snow is posing concerns of roof collapse throughout the Tri-State Area and it has the National Weather Service advising homeowners to begin clearing rooftops.

Civil engineer Richard Caspirien explains the frequency of heavy snow is the problem.

“Since we don’t have a break in between the periods of snow to the let the existing material liquefy and run off, we’re building up the snow load,” Caspirien tells WCBS 880 Long Island Bureau Chief Mike Xirinachs.

Kempadoo and George Isabella spent hours Monday morning cleaning a foot of snow off the flat roof of a house in New Rochelle.

“Too much ice, not enough drainage, gonna make the roof collapse,” Kempadoo said.

On Friday, Chopper 2 HD broadcast video of a roof collapse in Newark.

“Since Friday we’ve got over 300 calls. Cannot service them all,” said John Golina of FCC Contracting.

Golina had four roof-clearing crews making call after call in the suburbs and the city on Monday.

Any roofer will tell you that removing snow from a flat roof is a job best left for professionals because under the blanket of snow — is usually a slippery layer of ice.

“Heat from the buildings, be it commercial or residential, comes up through the roofline, melts it. At nighttime turns the liquid into ice again,” Golina said.

“I’ve seen people fall and get hurt, even a couple of roofers fall and get hurt.”

If you have a pitched roof snow buildup is less of an issue. You can use a so-called “roof rake” to remove snow, one small section at a time. That’s if you can find one. Area Home Depots and many other hardware stores are sold out, so some crews are improvising with shovels.

“We’re having a hard time ourselves with all this snow trying to find the rakes,” roofer Tony Trabucco said.

With the way this winter’s been, these crews don’t expect much downtime anytime soon.

Many “big box” stores have hired experts to measure the snow on their roofs, and make sure they’re not at risk of collapse.

Sick of the snow? Worried about your roof? Tell us about it in the comments section below.